Apparatus for changing pump liners



Feb. 2, 1960 w. R. BRADLEY, JR

APPARATUS FOR cmmcmc PUMP LINERS Filed April 27, 1955 Aug William R.Bradley, J0:

Inventor Attorney APPARATUS FOR CHANGING PUMP L William R. Bradley, Jr.,Tulsa, Okla, assignor, by mesne assignments, to Jersey ProductionResearch Company.

Application April 27, 1955, Serial No.-50.4,222

' 3 Claims. (Cl. 29-283) The present invention relates to means forremoving or installing the liners that are employed in reciprocatingpumps. It particularly relates to an apparatus for' rapidly andconveniently changing the liners that are employed in oil field slushpumps. The invention especially concerns an apparatus for changing theliners in slush pumps without requiring the removal of the piston rodsfrom the pumps. a i V Reciprocating pumps are well knownin the art andhave found particular application as slush pumps in well drillingoperations. The reciprocating pumps that are employed for thisparticular purpose are generally double acting pumps and furthermore areusually of the duplex or triplex type. The pumps, as their nameindicates, are used for supplying drilling mud to the drill bit at thebottom of a bore hole and for conveying the mud from this point back upto the earths surface. I

Inasmuch as the pressure that a slush pump must develop increases as abore hole increases in depth, it follows that means must be provided forchanging the pressure and delivery characteristics of the pump as adrilling operation progresses. Specifically, it has been the practice inthe industry to periodically change the cylinder liners and the pistonsin such pumps as the depth of a bore hole increased. Thus, it has beenthe practice to start any particular drilling operation with a slushpump that contains a relatively large diameter cylinder liner and pistonand to exchange the liner and piston for smaller sizes at intervalsduring the drilling operation. This procedure is repeated until the holehas reached its maximum depth, and in this way a pump of a givenhorsepower and speed may be adapted to deliver fluid or other drillingmud at substantially any desired pressure within the operating limits ofthe pump.

To date, several procedures and forms of apparatus have been employedfor changing the liners and pistons in reciprocating slush pumps. andapparatus require that the cylinder head of such a pump be removed as afirst step in getting at the liner and the piston. Then the liner spacerif any is'removed, and following this the piston and the piston rod areremoved. A suitable screw jack, hydraulic jack or other suitable meansis 'then inserted into the pump and is used to remove the old liner andto jack a new or replacement liner into position. Following-this, thepiston rod, the piston, the spacer and the cylinder head are replaced.

While the foregoing procedure is widely employed in the industry forreplacing cylinder liners and while'the procedure affords means forattaining the desired objectives, it is characterized by a number ofundesirable features. Specifically, it is always necessary to remove thepiston rod from a pump in order to replace its liner;

- and it is generally further necessary to repair, adjust or evenentirely replace the piston rod packing. Furthermore, the procedure istime consuming and therefore expensive.

The problem of changinga piston in a slush'pump has 2,923,055 PatentedFeb. 2, 1960 ice been recently simplified by the advent of a quickchange type of piston which enables the operator to change the pistonwithout removing the piston rod. Since the rod, however, must still beremoved in order to change the liner, little real advantage has beenrealized as a result of this type of piston insofar as removal orreplacement of the liner is concerned.

There is one form of apparatus which has been developed that permits aworn cylinder liner to be removed without prior removal of the piston orthe piston,

rod, but this tool is used only in those instances where it is notdesired to reuse the liner. The tool relies for its action on aplurality of teeth or jaw-like members that gouge into the liner andpermit the operator to draw the liner from the cylinder.

Thus, no procedure or apparatus has yet been developed to exchange thecylinder liner and piston in a reciprocating type pump without priorremoval of the piston rod from the pump. Accordingly, it is a particularobject of this invention to afford means for attaining this goal. Morespecifically, it is an object of the invention to provide an apparatuswhich enables the operator of a reciprocating piston-type pump to removeor replace a cylinder liner from such a pump without removing the pistonrod.

A complete understanding and presentation of the invention is bestunderstood by first briefly considering the structure and operation ofreciprocating piston type pumps and particularly reciprocating pumpssuch as are employed as slush pumps in oil well drilling operations.Accordingly, attention is directed to attached Figure l whichillustrates in partial cross-section a reciprocating pump of a typewhich is employed in drilling operations. Turning to the figure, thereare illustrated pump body 5, cylinder liner 6, piston rod packing glandassembly 7,

1 piston rod 8, sliding crosshead 9, crank shaft 10, herring All ofthese procedures bone gear 11, gear 12, jack shaft 13 and flywheel 14.The

piston, cylinder head, and liner spacer are not illustrated,

,belt to a suitable driving wheel not shown. 'Movement of the belt onthe flywheel 14 causes the jack shaft 13 to revolve and the jack shaftdrives the gear 12. Gear 12 drives herringbone gear 11, and gear 11 inturn causes crank shaft 10.to revolve. Motion and power from the crankshaft are translated into reciprocating motion of the piston rod 8 bymeans of crank 15, connecting rod 16, crosshead 9 and crosshead slidemembers 17.

Piston rod 8 normally causes a piston (not shown) to move in areciprocating manner from one end of cylinder'liner 6 to the other endof the liner. In so doing the piston causes liquid to flow in and out ofthe two chambers 20 and 21. It is apparent from the figure that the pumpillustrated therein is of a double acting type in that it simultaneouslyexerts a suction stroke in one of the aforesaid chambers and a dischargestroke in the other chamber. It will be appreciated that the chambers 20and 21 are in direct fluid communication through the ports 22 and 23 tosuitable sets of suction and discharge valves that are not shown.

As pointed out earlier in this description, it has until now beennecessary to remove the cylinder head as well as the .piston rod from areciprocating pump before it has been possible to remove or replace thecylinder liner'. As further pointed out earlier in this description/thepresent invention enables one to attain these objectives without removalof the piston rod. The particular apparatus that attains this objectiveand that constitutes the present invention is illustrated in Figures 1-3inclusive where:

' Figure 1 illustrates the novel device directly within a pump in theposition that it would occupy for removing a liner from a pump.

Figure 2 is a perspective view of the device which is illustrated inpartial cross-section in Figure 1.

Figure 3 is an end view of the apparatus in Figure 2 as it would appearin looking toward the puller hook end of the apparatus.

The apparatus of the invention is perhaps best illustrated in Figure 2where it may be seen that the apparatus includes at least two pullerhook members 31, two toggle arms 32, two links 36 and a rod cap 34.

Each puller hook member is preferably slightly curved so as to conformconveniently to the cylindrical shape of the cylinder liners that areemployed in any given reciprocating pump. Furthermore, each puller hookmember is provided with an outwardly flanged portion 40 which is adaptedto grip around one end of the cylinder liner.

The two puller hooks that are illustrated in the attached figures arecontinuously thrust laterally apart by means of spring loaded togglearms 32. Each One of these toggle arms is pivotally mounted to theinterior surface of one of the puller hooks, and the opposite end ofeach arm is slidably engaged with the other puller hook. In order toguide the free end of each toggle arm 32, arm guides 38 are provided onthe interior surface of each puller hook. These arm. guides form agrooved passageway which enables the free end of each toggle arm 32 tomove longitudinally with respect to the puller hooks. By means of thisfeature the puller hooks may be readily compressed together or extendedfrom one another without binding.

It is particularly noteworthy that the toggle arms 32 are laterallyspaced from one another (as is particularly illustrated in Figure 3) sothat a piston rod such as piston rod 8 may freely move between thesearms. It is further noteworthy that the pivoted end 37 of each togglearm is provided with a spring or other resilient means such as leafspring 42 shown in Figure 2 which is arranged to continuously urge thefree end of the arm away from the puller hook to which the arm isattached and toward the opposite puller hook.

Each toggle arm is connected to rod cap. member 34 by means of linkmembers 36. These links are pivotally or otherwise conveniently securedto each toggle arm.

and may be made adjustable in length so as to accommodate pumps thatpossess diiferent stroke lengths. Alternatively, the links 36 may bemade conveniently replaceable so that links of different lengths may beused when so desired. In any event the links should be of suitablematerial and strength such that the forces that are required to operatethe device are provided.

Rod cap 34 is provided with a central'passageway 33 pump is illustratedwith its piston head, piston and cylwhich is of a diameter large enoughto pass freely over the piston rod. Furthermore, the rod cap ispreferably provided with adjustable pins 39 which enable the operator tocenter the cap within a cylinder liner. Again, the rod cap may beprovided with means for mounting the ends of the links 36 in differentvertical positions, since it is particularly preferred that thesemembers be maintained substantially parallel to the longitudinal axis ofthe cylinder liner. As in the case of the toggle arms 32 and the pullerhooks 31, it is desirable that the rod cap 34 and the other componentparts of this device be made of a material and structure such that thedevice possesses suflieient strength for its aforedescribed use.

The invention is even better understood by reference to the manner inwhich it is employed in a pump installation. Accordingly, attention isparticularly directed toward a consideration of Figure l where body 5 ofa inder liner spacer removed. The apparatus of the invention isillustrated in this figure in the position that it would occupy in orderto remove cylinder liner 6 from within the pump body 5. Thus, theflanged members 40 of the two puller hooks 31 are depicted as engagingone end of the liner 6. Toggle arms 32 are shown urging the puller hooks31 outwardly against cylinder liner 6, and link members 36 connect thetoggle arms with the rod cap 34.

The adjustable centering pins 39 have been adjusted to center rod cap 34along the longitudinal axis of the liner 6, and nut 41 has been run upagainst the rod cap to make the entire assembly snug. In other words,nut 41 is run up against the surface of rod cap 34 until the flanges 40firmly engage the end of cylinder liner 6. It is apparent, of course,that nut 41 has to ride against that side of the rod cap which enablesthe nut to move the cap in the direction required to force the linerfrom the. pump. It is further apparent that the piston rod, crankshaftetc. are preferably positioned at the extreme end position of the pumpsstroke such that the entire stroke travel can be utilized to drive theliner from its position within the pump.

At this point power is applied to the pump, and piston rod 8 is causedto move longitudinally along the axis of the cylinder liner 6. It willbe appreciated that the necessary power may be obtained by utilizing thesame power source that is employed to run the pump during its regularoperation. It is preferred, however, that the piston rod be actuated inthis instance by hand for obvious safety reasons. Thus, one or morepersons can suitably and satisfactorily cause piston rod 8 to move byapplying power to the spokes of the flywheel 14. Alternatively, asuitable jack, crank or lever may be applied to the jack shaft 13 or tothe crank shaft 10. In any event movement of piston rod 8 causes flangemembers 40 to bear against the end of cylinder liner 6 and to thrust theliner from its position within the body 5. It is particularly noteworthythat the liner, once driven from its position within the cylinder,cannot be dragged back within the cylinder on the return stroke of thepump, since the piston rod rides freely through the rod cap in thisdirection.

To insert a cylinder liner within the pump body 5, a reverse butsubstantially identical procedure is employed. In this case the deviceis arranged within the cylinder so that the flanges 40 bear against theopposite end of the cylinder liner 6, and the nut 41 is placed in aposition relative to cap 34 such that is causes the flanges 40 to thrustthe liner within the pump. It will be appreciated that it will generallybe necessary to employ longer link members 36 for installing a cylinderliner than are necessary towithdraw a liner. As pointed out earlier thelinks may be made either adjustable in length, or they may be madereplaceable with longer links for this purpose.

In examining the apparatus in the various figures, it will be observedthat the use of the liner puller apparatus affords several uniqueadvantages. First, it enables an operator to replace a cylinder linerwith a minimum expenditure of labor and time. Second, it reducesmarkedly the wear that otherwise occurs to the threads on the pistonrods. Third, it obviates damage to the crosshead threads and to thepiston rod packing.

It will further be appreciated that a number of modifications andvariations may be incorporated within the apparatus without; departingfrom the spirit or scope of the invention. For example, a variety ofdifferent flange members may be. employed to grip the ends of thecylinder liners. Again, a number of puller hooks other than the twoillustrated may be employed if so desired. Likewise, a. variety oftoggle arms or other extensor-type members may be employed to maintainthe puller hooks ina spaced relation with respect to one another.

What is claimed is:

1. An apparatus for moving a cylinder liner within the cylinder of areciprocating type piston pump following removal of the cylinder headand piston but not the piston rod, said apparatus comprising at-leastone pair of hook members adapted to fit within said liner in adiametrically opposite relation, the hooked portion of each hook memberextending outward from said hook member and adapted to engage one end ofthe liner, a separate toggle arm pivotally attached at one end to theinner side of each book member, the opposite end of each toggle armextending toward the hooked portions of the hook members and terminatingagainst a radially opposite hook member, guide means on the inner sideof each said hook member and adapted to receive said opposite end ofsaid toggle arm in a longitudinally sliding relationship with said hookmember, a rod cap member adapted to fit within the cylinder liner andprovided with a hole so as to enable the piston rod to move freelytherethrough, a separate link member pivotally attached at one end to anintermediate point along the length of each toggle arm and at the otherend to said rod cap member, and means attachable to the piston rod forbearing against the rod cap member in a manner to urge the hookedportions of said hook members against said end of said cylinder liner.

2. An apparatus as defined in claim 1 including pin members attached tosaid rod cap member and adapted to center said rod cap member within thecylinder liner.

3. An apparatus as defined in claim 1 including resilient means arrangedto continuously urge said hook members radially away from thelongitudinal axis of the cylinder liner.

References Cited in the file of this patent UNITED STATES PATENTS435,594 Teetzel Sept. 2, 1890 683,411 Norden Sept. 24, 1901 963,603Lunceford July 5, 1910 2,487,902 Stout Nov. 15, 1949 2,566,507 WalravenSept. 4, 1951 2,613,983 Knudsen Oct. 14, 1952 2,688,183 Oberley et a1.Sept. 7, 1954 2,697,872 Armstrong Dec. 28, 1954 2,706,658 Jewell Apr.19, 1955 2,715,261 Williams Aug. 16, 1955

